This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Uterine leiomyoma (fibroids) are the most common gynecologic benign tumors in the premenopausal women. Fibroids cause significant morbidity for women and substantial economic impact on healthcare systems. African American women have three to four times higher prevalence of uterine leiomyoma than white women. Evidences suggest that vitamin D deficiency is ten times higher in African American women than white women. But the link between hypovitaminosis D and development of uterine leiomyoma is not known. Additionally, the molecular mechanisms of how vitamin D regulates growth of uterine leiomyoma are yet to be elucidated. Vitamin D is known as a potent inhibitor of growth and its deficiency stimulates cell proliferation. The long-term objective of this study is to determine the molecular mechanism by which vitamin D target the genes that are involved in leiomyoma growth and to develop vitamin D-based preventative and therapeutic approaches for uterine fibroids. This study will determine the correlation between vitamin D and risk associated with development and progression of uterine leiomyoma particularly in African American women.